To be clear, my point is not to draw a false equivalence between armed police raids in the UK and the US. I would, however, say that the problem of appropriately responding to a potential armed threat isn't exactly solved in either country, if that's even possible.
Here's yet another example on a quick Google search, if you're still unconvinced that this occurs in the UK: https://www.hertfordshiremercury.co.uk/news/hertfordshire-ne...
> "No action will be taken against the occupants of a Hemel Hempstead home that was raided by armed police after a mystery phone call."
> "One witness described armed officers going inside a home shortly before putting two people inside the home in handcuffs and in the back of a police car."